To provide a resistance welding machine capable of easily preventing bare wire parts of a covered conductor from being loosened while welding the covered conductor to a welding material, and reducing the number of steps.

A pair of welding guides 30 comprising a first guide 31 and a second guide 32 for holding the bare wire parts 13 of the covered conductor 10 at the predetermined width from the direction orthogonal to the pressing direction of a pair of electrodes 20 comprising an upper electrode 21 and a lower electrode 22 are provided. At least one of the pair of welding guides 30 is attached/detached to/from notched parts 33 for releasing an intermediate part 13c by holding a free end part 13a and a root part 13b of the bare wire parts 13 on holding ends 31a and 32a abutted on the bare wire parts 13. In this resistance welding machine, the attaching/detaching electrode, e.g. the upper electrode 21 in this case out of the pair of electrodes 20 enters/exits to and from the notched parts 33 across the intermediate part 13c of the bare wire parts 13 during the attachment/detachment.